//像素比
var iScale = 1;
iScale = iScale / window.devicePixelRatio;
//会导致弹出窗变小
//document.write('<meta name="viewport" content="width=device-width,user-scalable=no,initial-scale=' + iScale + ',minimum-scale=' + iScale + ',maximum-scale=' + iScale + '">');
    
//动态设置文字大小
var iWidth = document.documentElement.clientWidth;
document.getElementsByTagName('html')[0].style.fontSize = iWidth / 18.75 + 'px';	